Group A streptococcal infection
A group A streptococcal infection is an infection with group A streptococcus (GAS). Streptococcus pyogenes comprises the vast majority of the Lancefield group A streptococci, and is often used as a synonym for GAS. However, S. dysgalactiae can also be group A. S. pyogenes is a beta-hemolytic species of Gram positive bacteria that is responsible for a wide range of both invasive and noninvasive infections.
|Group A streptococcal infection|
Infection of GAS may spread through direct contact with mucus or sores on the skin. GAS infections can cause over 500,000 deaths per year. Despite the emergence of antibiotics as a treatment for group A β-hemolytic streptococcus, infection of GAS is an increasing problem, particularly on the continent of Africa.
There are many other types of streptococci (species of Streptococcus), including group B streptococcus (Streptococcus agalactiae) and Streptococcus pneumoniae, which cause other types of infections and should not be confused with group A strep. Several virulence factors contribute to the pathogenesis of GAS, such as M protein, hemolysins, and extracellular enzymes.